DataGridView控件添加鼠標選定ToolTip顯示合計

[csharp]
/// <summary>  
        /// DataGridView多行選擇求和  
        /// </summary>  
        /// <param name="myDataGridView">要求合計提示的DataGridView控件</param>  
        /// <param name="TooLar">傳入的ToolTip控件.</param>  
        /// <returns></returns>  
        public bool DataGridViewSum(DataGridView myDataGridView, ToolTip TooLar) 
        { 
            if (myDataGridView.SelectedCells.Count < 2) 
            { 
                TooLar.RemoveAll(); 
                return false; 
            } 
            //如果選擇的單元格是全部，且大於：１００００，則認為是不是求合計的操作  
            if (myDataGridView.SelectedCells.Count > 10000 && myDataGridView.SelectedCells.Count == myDataGridView.GetCellCount(DataGridViewElementStates.None)) 
            { 
                TooLar.RemoveAll(); 
                return false; 
            } 
  
            DataSet DS = new DataSet(); 
            DataTable DtGroup = new DataTable("DtGroup");//保存列名  
            System.Collections.ArrayList NameMaxLength = new System.Collections.ArrayList();//保存DT中列名的長度  
            System.Collections.ArrayList ValueMaxLength = new System.Collections.ArrayList();//保存DT中列名的長度  
            DataTable DT = new DataTable("DT");//保存列名及數據  
            DtGroup.Columns.Add("ColumnName", System.Type.GetType("System.String"));//字段名  
  
            DT.Columns.Add("ColumnName", System.Type.GetType("System.String"));//字段名  
            DT.Columns.Add("ColumnValue", System.Type.GetType("System.Decimal"));//字段值  
  
            foreach (DataGridViewCell DC in myDataGridView.SelectedCells) 
            { 
                if (DC.ValueType.Name.ToLower() == "decimal" || DC.ValueType.Name.ToLower() == "int32") 
                { 
                    DataRow DR; 
                    DR = DT.NewRow(); 
                    DR["ColumnName"] = myDataGridView.Columns[DC.ColumnIndex].Name; 
                    if (DC.Value == null) 
                    { 
                        DR["ColumnValue"] = 0; 
                    } 
                    else 
                    { 
                        DR["ColumnValue"] = DC.Value; 
                        ValueMaxLength.Add(DC.Value.ToString().Length); 
                    } 
                    DT.Rows.Add(DR); 
                    //在現有DtColName中查找是否包含了這個列名  
                    if (DtGroup.Select("ColumnName='" + myDataGridView.Columns[DC.ColumnIndex].Name + "'").Length == 0) 
                    { 
                        DataRow DR1; 
                        DR1 = DtGroup.NewRow(); 
                        DR1["ColumnName"] = myDataGridView.Columns[DC.ColumnIndex].Name; 
                        DtGroup.Rows.Add(DR1); 
                        NameMaxLength.Add(myDataGridView.Columns[DC.ColumnIndex].Name.Length); 
                    } 
                } 
            } 
            DS.Tables.Add(DT); 
            DS.Tables.Add(DtGroup); 
  
            DataRelation dRelation = new DataRelation("dRelation", DS.Tables["DtGroup"].Columns["ColumnName"], DS.Tables["DT"].Columns["ColumnName"]); 
            DS.Relations.Add(dRelation); 
            DtGroup.Columns.Add("ColumnSum").Expression = "sum(child(dRelation).ColumnValue)"; 
            string decSum = DT.Compute("sum(ColumnValue)", "").ToString(); 
  
            NameMaxLength.Add("總合計：".Length); 
            ValueMaxLength.Add(decSum.Length); 
            DtGroup.AcceptChanges(); 
            string Tall = ""; 
            NameMaxLength.Sort(); 
            ValueMaxLength.Sort(); 
            int NameMaxLen = 0; 
            NameMaxLen = int.Parse(NameMaxLength[NameMaxLength.Count - 1].ToString()); 
            int ValueMaxLen = 0; 
            ValueMaxLen = int.Parse(ValueMaxLength[ValueMaxLength.Count - 1].ToString()); 
            for (int i = 0; i < DtGroup.Rows.Count; i++) 
            { 
                string strOneLine = ""; 
                strOneLine = (DtGroup.Rows[i]["ColumnName"].ToString() + "：").PadRight(NameMaxLen + 1, '　'); 
                strOneLine = strOneLine + DtGroup.Rows[i]["ColumnSum"].ToString().PadLeft(ValueMaxLen, ' '); 
                Tall = Tall + strOneLine + System.Environment.NewLine; 
            } 
            Tall = Tall + "總合計：".PadRight(NameMaxLen + 1, '　') + decSum.PadLeft(ValueMaxLen, ' '); 
  
            myDataGridView.ShowCellToolTips = false; 
            TooLar.ToolTipIcon = ToolTipIcon.Info; 
            TooLar.IsBalloon = true;//汽球形狀  
            TooLar.ToolTipTitle = "鼠標選定合計信息："; 
            TooLar.UseAnimation = true;//使用動畫效果  
            TooLar.UseFading = true;//淡入淡出效果  
            TooLar.BackColor = Color.Wheat;//工具提示的背景色  
            TooLar.AutoPopDelay = 10000;//顯示時間  
            TooLar.RemoveAll(); 
            TooLar.SetToolTip(myDataGridView, Tall); 
            DT.Dispose(); 
            DtGroup.Dispose(); 
            DS.Dispose(); 
            GC.Collect(); 
            return true; 
        }